258 Mn. J. S. GARDINER ON TITE PERTOBATE [^'P^- 5, 



variety ; on shoals a few fathoms submerged, the latter is often 

 very considerable, one shoal off Oinafa, Eotuma, with 2-4 fathoms 

 of water, giving seven species, while I have been able to identify 

 only four from the reefs and boat-channel of that island. J'rom 

 Funafuti, three species are recorded from 35 fathoms and one from 

 30 fathoms. 



1. Madbepora cbateeifobmis, n. sp. (Plate XXIII. fig. 1.) 



The corallum is in the form of an oval-shaped cup 8 by 10 cm. 

 in diameter, and about 1-5 cm. deep, with one subcentral stem on 

 the underside ; its edge is about 3 mm. thick, and formed by a 

 mass of budding corallites. The epitheca is very evenly continued 

 underneath to the edge of the cup and shows a number of con- 

 centric lines of growth. The inner part of the cup is crowded 

 with small, very even-sized corallites : these in places may form 

 short lines of rather more prominent corallites, but there is no 

 greater approximation towards the typical axial corallite of the 

 Madrepora than there is in many of the Turbinaria. The corallites 

 are tubular, 2-3 mm. in length by about 1 mm. in diameter, and 

 somewhat appressed to the walls of the cup ; the upper openings 

 of the calices are •4-*5 mm. in diameter, and there are usually 

 7 in 1 cm. Grenerally neither septa nor columella can be distin- 

 guished, but there are often some larger spines at the edge 

 of the calice, which indicate their position. The walls of the 

 corallites are covered with relatively long, rough, flattened, blunt 

 spines, which in places give rise to irregular striations. The 

 ccenenchyma is a rather coarse reticulum, covered \^ith similar 

 spines ; it is well developed at the edges of the cup, but completely 

 hidden by the tubular corallites within. 



Funafuti ; lagoon shoal. 



There is only one specimen, which may be the young form of 

 some previously described species, but it does not appear like the 

 incrusting base of a colony, nor do its corallites correspond to the 

 descriptions of those of any of the species described in the British 

 Museum Catalogue. The colony, if it is, as I believe, adult, shows 

 an approach to the Turhinana, but, if young, indicates a stage 

 not far from that from which the Turbinaria and the Madrepora 

 diverged in their development. 



2. Madrepora secunda, Dana (2). 



The specimen, which is about 13 cm. high, very closely resembles 

 Dana's description. The branches are, however, more crowded and 

 grow almost vertically. The primary septa are distinct, the 

 directives being more prominent. 



Funafuti ; outer reef. 



3. Madrepora rottimana n. sp. (Plate XXIII. fig. 2.) 



Corallum massive, of broad plates, formed by the fusion of 

 branches radiating from a short and stout pedicle. Two to four 

 plates thus formed generally arise from the pedicle and radiate 



